Frosty Loc: Minnesota

Maybe a dumb question, but here goes.
If you have two cameras with the same number of pixels but with different size sensors. Will the difference only be in noise at low light or are there other differences? Will enlargements to a moderate size be any different if both photos are taken in good lighting?

While I'm at it, what would be the difference between a camera with a CCD sensor vs one with the SAME size CMOS sensor? A professional photographer at a camera shop told me there are two reasons why manufactures have gone from CCD to CMOS. One reason is that the CMOS sensors are a lot cheaper to make. The second reson is that the CCD uses more power and people like wedding photographers didn't like CCDs because they draw more battery power and heat up the camera over time which affects the photos. He implied that the CCD was a better sensor but not used for the above reasons. Anyone know about this. He sold me a camera with a CCD sensor.

Cdouthitt Loc: Traverse City, MI

Frosty Loc: Minnesota

Thank you Cdouthitt. I think I get it. The CCD produces a slightly better image but the difference is almost undetectable. Whereas the CMOS has several other advantages.

Do you know the answer to the first question, the one about the same type of sensor with the same number of pixels but of different physical sizes, say a 1/1.7 vs an APS-C?

GoofyNewfie Loc: Kansas City

If the cameras are both of about the same age, technology-wise, the camera with the larger sensor (and larger pixels) will handle noise better. I did a test a while back and compared the Nikon D700 full-frame, the same age D300 (DX sensor) and the newer D7000 (DX sensor). At higher ISOs the D700 blew the D300 away, but the image quality of the D7000 was pretty close to the D700.

There is a bigger size difference between the 1/1.7 and APS-C sensors. I think it would take some amazing technology to get the high ISO quality between those the same, even if comparing old/new models. With smaller prints though, you may not see the difference.

Another thing is that with an equivalent focal length lens, the smaller sensor camera will give greater depth of field at the same aperture.
That's great news if you want to shoot macro (up to the point where diffraction degrades your image), but if you want shallow depth of field in, say, a portrait, the larger sensor camera will be a better choice given the lenses are of equivalent focal length.

Comparing a full-frame camera to a micro 4/3rds:

The so-called normal lenses of each are 50 (FF) and 25 (M4/3).
To get the same depth of field as the full-frame camera using the 50mm at f/2.8, you would have to use f/1.4 on the 25mm lens of the M4/3 camera.
With a 1/1.8 size sensor you would need a 10mm f/0.6 lens.
I think that would be pretty close to the 1/1.7.

Cdouthitt Loc: Traverse City, MI

Frosty Loc: Minnesota

Thank you GoofyNewfie. It appears that besides considering noise, one should also factor in focal distance, depth of field, weight and intended use when selecting a camera. It seems that for some purposes, the smaller sensor may be best.

Thanks again

Frosty Loc: Minnesota

Thank you again Cdouthitt.

I read the link you provided. I think I will need to study it a bit to really comprehend all of it. It really answers a question I have thought about for some time.

Peekayoh Loc: UK

These are moot points really. The CCD Sensor in the modern camera has largely disappeared due to the big advantages of CMOS technology. The main advantage of CCD was lower noise (only at low ISOs) but the latest CMOS Sensors are all pretty good in this regard and the CMOS advantages made it pointless to continue with developing CCDs. CCDs are still found in MF cameras because that's what they are stuck with and the small market for those cameras make it hard to develop new technologies.

Forget the number of pixels and just think in terms of Sensor size. Given the same generation of technology, a larger Sensor is always preferable to a smaller one.

oldtigger Loc: Roanoke Virginia-USA

I found this rather informative in regards to noise vs pixel size vs sensor size (may 2015)
http://www.dpreview.com/articles/5365920428/the-effect-of-pixel-and-sensor-sizes-on-noise

Peekayoh Loc: UK

Good find Oldtigger. I've said the same thing many times here but the myth that small pixels are bad lives on.

oldtigger Loc: Roanoke Virginia-USA

it appears to be unbiased.

CO

When stopping down the aperture, diffraction will start to soften the images of sensors with smaller pixels before sensors with larger pixels. I don't stop the aperture down more than f/8 with my crop sensor cameras. With full frame cameras with larger pixels you could stop down more.

Peekayoh Loc: UK

No it won't! Diffraction is an Optical phenomenon which has nothing to do with pixel size. Larger Sensors have an advantage with regard to diffraction in that the effect is less noticeable when printing at the same size (smaller Sensors require more enlarging).

CO

Yes, diffraction is an optical phenomenon which has nothing to do with pixel size however smaller pixels are affected by diffraction before larger pixels when stopping down the aperture. This website has an excellent illustration of this. They show a grid illustrating the pixel size of a Nikon D2x camera and how it's affected by diffraction at apertures of f/8, f/11, and f/22.
http://www.lonestardigital.com/aperture_diffraction_limits.htm

Peekayoh Loc: UK

The linked article is pretty simplistic and the illustrated single pixel clean light beam (their words) simply doesn't exist in the real world.

Consider the same lens on the 16Mpix D4 and on the 36Mpix D800; the diffracted light reaching the sensor is exactly the same in both scenarios, this is indisputable. What is different in the post process images is the extra resolution resulting from the smaller pixels of the D800. With smaller apertures the fine detail becomes progressively more diffraction degraded but that detail was never present in the D4 to begin so we are no worse off. Actually we are better off because, even though degraded, the detail is still contributing to the image.

In your first post you stated I don't stop the aperture down more than f/8 with my crop sensor cameras. With full frame cameras with larger pixels you could stop down more which is partially true. The true bit is that the FF camera has at least a stop advantage in diffraction degradation but this is not a result of larger pixels, it is the result of the larger sensor which requires less enlargement. Larger pixels equate to less resolution not to less diffraction.